Engineering topics
Publications and source records attributed to Stroke, G. W..
Holographic computing principles make possible image improvement and synthesis in many cases of current scientific and engineering interest. Examples are given for the improvement of resolution in electron microscopy and 3-D reconstruction in electron microscopy and X-ray crystallography, following an analysis of optical versus digital computing in such applications.
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The speed of the holographic image deblurring method has recently been further enhanced by a new speed in the realization of the powerful holographic image-deblurring filter. The filter makes it possible to carry out the deblurring, in the optical computer used, in times of the order of one second. The experimental achievements using the holographic image-enhancement method are illustrated with examples ranging from out-of-focus or motion-blurred photographs, including 'amateur' photos recorded on Polaroid film, to the sharpening of the best available electron micrographs of viruses. Images recorded with X-rays, notably from rocket-borne photos of the sun, and out-of-focus photographs from cameras in NASA satellites have been similarly deblurred.
Applications of the optical computer include an approach for increasing the sharpness of images obtained from the most powerful electron microscopes and fingerprint/credit card identification. The information-handling capability of the various optical computing processes is very great. Modern synthetic-aperture radars scan upward of 100,000 resolvable elements per second. Fields which have assumed major importance on the basis of optical computing principles are optical image deblurring, coherent side-looking synthetic-aperture radar, and correlative pattern recognition. Some examples of the most dramatic image deblurring results are shown.
In 1968, Dicke had suggested that multiple-pinhole camera systems would have significant advantages concerning the SNR in X-ray and gamma-ray astronomy if the multiple images could be somehow synthesized into a single image. The practical development of an image-synthesis method based on these suggestions is discussed. A formulation of the SNR gain theory which is particularly suited for dealing with the proposal by Dicke is considered. It is found that the SNR gain is by no means uniform in all X-ray astronomy applications.
Discussion of the physical and mathematical fundamentals, performance capabilities and potential applications of image deblurring by holography. It is shown that a blurred photograph may be deblurred and a sharpened image extracted from it because the 'blurring' in the original photograph did not irretrievably lose the imaging information, notably in the spatial-frequency regions required for faithful imaging and for high resolution. The principles of optical image deblurring are highly mathematical in nature. One of the most important applications of holographic image deblurring is shown to be the sharpening of electron micrographs of biological specimens beyond the ultimate that can be achieved with even the most powerful instruments available.
High resolution holographic image deblurring methods involving coherent optical analog processing and Fourier transform division filter
Photographic image deblurring method, using image forming holograph and amplitude weighting transparency
Laser-light spatial-domain scanning function for deconvolution of blurred photographs using point-spread and holographic Fourier transform division filter
Spatial domain deconvolution by laser scanning of blurred photographs, using holographic Fourier transform division filter and photoelectric integration
Image deblurring and aperture synthesis using a posteriori processing by Fourier transform holographic spatial filtering
Extended source Fourier transform holography for single image synthesis of multiple identical images produced by multiple pinhole camera in X ray astronomy
Motion-distorted photograph deblurring method using extended range holographic Fourier transform division
Optical imaging systems achieving aperture synthesis by lensless Fourier transform holography, noting X ray astronomy, ultrasonic and space applications
Holographic optical computing image restoration method for a posteriori deblurring of photographs
Corrective image deconvolution of smearing caused by extended instrument functions in optical imaging possible by holographic Fourier transform division
Holographic technique for restoration of third- dimension information in recording of conventionally focused photographs
Nonhomogeneous Helmholtz equation for optical gratings with perfectly conducting boundaries solved, using distribution theory